Upgrading or replacing the wheels and tires on a classic W123 Mercedes Benz can significantly enhance its appearance and handling. However, ensuring proper fitment is crucial to avoid clearance issues and maintain optimal performance. Understanding wheel offset, tire sizes, and their impact on your W123 is essential for any wheel modification.
When considering new wheels for your W123 Mercedes Benz, the original equipment (OE) specifications provide a solid starting point. The largest OE size listed for the W123 was typically a 7 x 15 inch wheel with a 25 mm offset (ET25). Mercedes-Benz utilized a 5 x 112 bolt pattern and a hub-centric design for these models. A common challenge arises when moving to bigger or wider tires, as these often come with different offsets. Offset, stamped as “ET” on OE wheels (Einpresstiefe – German for “insertion depth”), dictates how far the wheel sits in or out of the wheel well.
For the W123 Mercedes Benz, inboard clearance, particularly concerning the suspension components, is a primary concern. If you opt for a wider tire and a wheel with a smaller offset, you can mitigate some of these clearance problems. This is because a lower offset effectively moves the wheel’s center, and consequently its inboard edge, further outward, away from the suspension. For instance, utilizing Mercedes-Benz wheels with the correct bolt pattern and hub diameter, and selecting those with a lower offset, can eliminate the need for wheel spacers to achieve the desired outboard positioning.
Replica Mercedes-Benz wheels are available with varying, including lower, offsets such as 15 mm and 23 mm. These can offer a direct fit solution for achieving a wider stance without clearance complications. Resources like the Wheel Offset Calculator provide valuable tools to visualize and calculate changes in inboard and outboard clearance based on different wheel and tire combinations.
It’s important to remember that altering tire width and wheel centerline will influence your W123’s handling characteristics and potentially its tracking, even if the car is properly aligned. Detailed calculators, such as the one available at Custom rims, wheel tire packages for your ride – RIMSnTIRES.com, can illustrate the precise changes needed. For example, upgrading from a common 195/70-14 tire on a 6×14 ET30 wheel to a 205/55-16 on a 7.5×16 ET15 wheel requires approximately 4 mm more inboard clearance while still maintaining speedometer accuracy.
For those seeking a subtle reduction in ride height for their W123 Mercedes Benz, “modest” lowering can be achieved by switching to spring pads with fewer ‘nubs’ or ‘bumps’. This method, typically yielding a lowering of 8-15 mm depending on the existing spring pads, avoids the necessity of installing new or cutting existing springs.
Choosing the right wheel and tire combination for your W123 Mercedes Benz requires careful consideration of offset, size, and desired handling characteristics. Utilizing available calculators and understanding OE specifications will ensure a successful and aesthetically pleasing upgrade.
